MQTT Subscribe and Unsubscribe using Simcom modules

Simcom SIM7XXX modules has support for the MQTT feature using the AT Commands.

To subscribe to a topic with Simcom modules,

• Connect to the MQTT browser
• Subscribe to a topic using the AT+SMSUB command.
• Unsubscribe from a topic using the AT+UNSUB command.

Related Topics

• How MQTT works?
• MQTT – Connect to Broker
  • Connect to Eclipse public MQTT Server
• MQTT Publish
• MQTT Subscribe

Try AT Command Tester tool to test MQTT features with the Simcom Modules. In below example,

• With one instance of the AT Command Tester tool, a MQTT connection is established to ‘test.mosquitto.org’ server using the Simcom SIM7080G module.
• With another instance of the AT Command Tester tool, a MQTT connection is established to ‘test.mosquitto.org’ using the PC client.
• The MQTT PC client publishes to the topic ‘SensorReadings’.
• The Simcom MQTT client is subscribed to the topic ‘SensorReadings’ and so receives the data published by the PC MQTT client.

Keywords: Module , M2M , GPRS , 3G , through AT commands,